Patent GB-906662-A (GB)
Title: Improvements in or relating to seam formation indicator apparatus for sewing machines
IPC: D05B19/00
Filed: 1959-03-19
Abstract: 906,662. Sewing-machines. PFAFF A.G., G. M. March 19, 1959 [March 19, 1958], No. 9513/59. Class 112. A zig-zag sewing-machine is provided with a plurality of indicating means operatively associated with respective means for influencing the stitch pattern form, and the arrangement is such that the required stitch pattern is indicated on collective stitch pattern indicia by the cooperation of said indicating means. In Fig. 1 six pattern cams 7 are fixed to a rotatable shaft 4. An arm 9, pivoted at 12 and connected to a link 16 associated with means for varying the stitch width, has pivoted thereto at 14 six cam follower levers 18. A spindle 24 has secured thereto six fingers 20 which are helically arranged and are angularly spaced at <1>/7th of 360 degrees apart. A knurled-edged wheel 26 fixed to spindle 24 is releasably held at angles of <1>/7th of 360 degrees apart, when one of the fingers 20 abuts the tail of a follower 18 to engage the nose 28 of the latter with its associated cam 7, rotation of which thus causes said tail to slide upon the abutting finger and arm 8 to swing about pivot 12. When none of the followers is abutted by a finger 20, the stitch width means may be adjusted manually. An arm 11 pivoted at 13 and connected by a link 17 to stitchposition varying means, has pivoted thereto at 15 six followers 19 which are similar to the followers 18 and which co-operate with fingers 21 carried by a spindle 25 rotatable by means of a wheel 27. Spindle 24 is coupled by 1: 1 gearing to a rotatable spindle 36 fixed axially to a drum 39. Spindle 25 is coupled by 1: 1 gearing to a rotatable spindle 37 which is journalled axially in drum 39 and which carries a hollow, transparent cylinder 42 arranged coaxially around drum 39. The surface of drum 39 is provided with representations of the possible stitch forms arranged in seven axial rows b0 to b6, each of which corresponds to one operative position of the wheel 26, and seven radial rows l0 to l6, each of which corresponds to one operative position of the wheel 27. The surface of cylinder 42 is formed with seven diagonal markings 51 corresponding to the rows l0 to l6. At each movement of the wheel 26 one of the rows b moves under a window formed in a cover, and each movement of wheel 27 brings one of the markings 51 under the window. The stitch diagram covered by said marking indicates the stitch pattern producible by the particular setting of the wheels 26 and 27, the position b0, l0 representing the setting for manual adjustment. In a modification, Fig. 5, arm 11 replaced by two arms 111 and 153 pivoted at 113 and connected by respective links 117, 154 to means for varying the stitch position and the work feed. Pivoted on arm 111 are four cam follower levers arranged to co-operate with four fingers carried helically on a spindle 125 at <1>/5th of 360 degrees apart. Spindle 125 is rotatable by a wheel 127 to bring said followers in succession into engagement with their respective cams. Pivoted at 155 on arm 153 are two follower levers 156 arranged to co-operate respectively with two fingers 158 carried by a sleeve 157 journalled on spindle 125. An arm 159 carried by sleeve 157 is connected by a link 160 to a lever 161 pivoted at 162. In the middle position of lever 161 both fingers 158 are disengaged from the followers 156, and in the respective end positions one or the other finger 155 engages its corresponding follower 156. A drum 139 rotatably coupled with the wheel for adjusting the stitchwidth controlling means is provided, as in the first embodiment, with six axial rows b0 to b6 of stitch diagrams. Drum 139 is also provided with five groups of circumferential rows l0 to l4 corresponding to the respective operative positions of the wheel 127. Each group consists of three rows t1, t0 and t2 corresponding to the left-hand, centre and right-hand positions, respectively, of the lever 161. A transparent, hollow cylinder surrounding drum 139 bears five diagonal markings 151 each of which is aligned with one of the groups l. Each movement of drum 139 brings one of the rows b under a window 149 in a cover 150, and each movement of the hollow cylinder brings one of the markings 151 under the window. Lever 161 is mechanically coupled to a plate 164 which is slidably mounted on cover 150 and is formed with five pointers 163 visible in the window. Each pointer is aligned with one of the groups I and moves with the lever 161 to indicate which one of the three diagrams covered by a marking 151 corresponds to the pattern produced by the setting of the controls. In a further modification arm 11 and the cam followers and fingers associated therewith are as in the first embodiment. Arm 9 is replaced by two arms as in the second embodiment. One arm carries four cam followers and is connected to the stitch-width controlling means. The other arm carries two cam followers and is connected to the work-feed controlling means. The six followers are arranged to co-operate with six fingers 20 as in the first embodiment. The indicating drum 239, Fig. 10, rotatably coupled to wheel 26, is formed with seven circumferential rows l0 to l6 of stitch diagrams as in the first embodiment. The drum is also formed with seven axial rows corresponding respectively to the six fingers 20 and the vacant space in the latter. Four of the axial rows b1 to b4 correspond to the cams controlling the stitch width, two rows t and t2 correspond to the cams controlling the work feed, and the row b0, t0 corresponds to the free position of the arms. The stitch width and work feed cannot be controlled simultaneously as in the second embodiment. Specification 906,661 is referred to.